FisMat2017 - Submission - View

Abstract's title: Dynamical Casimir effect in quantum information processing and in quantum thermodynamics
Submitting author: Giuliano Benenti
Affiliation: Univ. Insubria, Como, INFN, Milano, and CNR
Affiliation Address: Center for Nonlinear and Complex Systems, Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, 22100 Como, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano, Italy, and NEST, Istituto Nanoscienze-CNR, 56126 Pisa, Italy
Country: Italy
Oral presentation/Poster (Author's request): Poster
Other authors and affiliations:
Abstract

The search for high-speed operations is vital in quantum information. The clock time of a quantum computer, that is, the time for the execution of a quantum gate, should be much shorter than the decoherence time scale to allow fault-tolerant quantum computation. Moreover, the enhancement of transmission rates in quantum channels is crucial to widen the applicability domain of quantum cryptography and quantum networks. The possibility of speeding up quantum operations is nowadays offered by circuit quantum electrodynamics, where one can address the ultrastrong coupling regime of light-matter interaction. In this regime, the coupling strength becomes comparable to, ore even exceeds the resonator frequency. This regime has also interesting properties on its own, such as the emergence of a strongly correlated light-matter ground state.

A related problem is the detection of the dynamical Casimir effect (DCE), namely the generation of photons from the vacuum due to time-dependent boundary conditions or, more generally, as a consequence of the nonadiabatic change of some parameters of a system.
We discuss strategies  to amplify and thus improve the visibility of the DCE in a parametrically driven system via precisely tailored timing of the matter-field interaction.
Moreover, we demonstrate, in the regime of ultrastrong matter-field coupling, the strong connection between the DCE and the performance of quantum-information protocols.
Finally, we discuss the relevance of the DCE in quantum thermodynamics and show that the DCE, which is unavoidable in any finite-time thermodynamic cycle, forbids in cooling protocols the attainability of the absolute zero of temperature, even in the limit of an infinite number of cycles.

References:

[1] G. Benenti, A. D’Arrigo, S. Siccardi and G. Strini, “Dynamical Casimir effect in quantum-information processing”, Phys. Rev. A 90, 052313 (2014).

[2] G. Benenti and G. Strini, “Dynamical Casimir effect and minimal temperature in quantum thermodynamics”, Phys. Rev. A 91, 020502(R) (2015).

[3] F. Hoeb, F. Angaroni, J. Zoller, T. Calarco, G. Strini, S. Montangero and G. Benenti, “Optimal amplification of the dynamical Casimir effect in a parametrically driven system”, preprint.